Oil burner apparatus



Dec. 21, 1965 J. c. H. PARIS 3,224,682

OIL BURNER APPARATUS Filed May 1, 1962 2 Sheets-Sheet 2 Fig.3

BY 1 ZR;

AGENT 42 INVENTOR:

JEAN CAMILLE HIPPOLYTE PARIS United States Patent 3,224,682 OIL BURNERAPPARATUS Jean Camille Hippolyte Paris, 152 Champs-Elysees, Paris,France Filed May 1, 1962, Ser. No. 191,594 Claims priority, applicationFrance, May 3, 1961, 860,596; Nov. 17, 1%1, 879,264 6 Claims. (Ci.239-4273) My present invention relates to a device, such as an oilburner, in which streams of two fluids are to be intimately commingledwithin a mixing chamber.

An object of this invention is to provide an improved mixing device ofthis character adapted to insure a thorough in-termingling of theparticles, e.g. as required in a burner designed to operate with asilent, substantially soot-free flame.

I have found, in accordance with the instant invention, that this objectcan be realized in a simple and effective manner by the provision of aset of annular baffles spacedly surrounding the outlet end of a nozzlewithin a substantially but not necessarily exactly cylindrical shellhaving an open end beyond the nozzle outlet, these baffles forming oneor more outwardly diverging channels for a fluid (such as combustionair) to be admixed with another fluid (e.g. fuel oil) discharged in asubstantially conical stream from the nozzle. The baflles, beingcentrally symmetrical, serve to suppress turbulence at the nozzle bydividing the air flow into a primary branch hugging the nozzle and asecondary branch directed outwardly toward the inner shell wall by wayof the aforementioned channel or channels, the latter air flow beingultimately combined with the conical nozzle spray at a location closerto the open end of the shell so that substantially the entire air inputis utilized without losses. If the nozzle and the shell are sodimensioned that the conical spray reaches the shell wall ahead of theopen end, the outwardly diverted secondary air flow may have sufficientforce to penetrate the cone of rarefied fuel in the zone ofintersection; other-wise it will be desirable to provide specialdeflecting means, such as an inturned ledge at the open end of theshell, for directing this secondary air toward the cone axis. The numberof baffles may vary with the dimensions of the burner, yet theypreferably include an inner baflle and at least two outer baflies withaxially and radially staggered edges facing the oncoming air flow.

The invention will be described hereafter with reference to theaccompanying drawing in which:

FIG. 1 is a side-elevational view, partly in longitudinal section, of anoil burner embodying the invention;

FIG. 2 is a sectional view similar to that of FIG. 1, illustrating amodification;

FIG. 3 is a view similar to FIG. 2 showing a further modification;

FIG. 4 is a view taken on line IVIV of FIG. 3;

FIG. 5 is a fragmentary sectional view similar to that of FIG. 3 butshowing still another embodiment; and

FIG. 6 is a view taken on line VIVI of FIG. 5.

In FIG. 1 I have shown an oil burner comprising a conventional nozzle 1forming the terminal part of a conduit which extends from a controllablesource (not shown) of fuel oil under pressure. Nozzle 1 is coaxiallysurrounded by a cylindrical shell 6 and has an outlet 1a designed toemit a stream of atomized fuel oil A in a conical spray with apex anglea toward the open end of the shell. An air stream B directed toward thatopen end is created within the shell 6 by suitable forcedcirculationmeans such as a blower 7.

A set of annular baffles 3, 4 and 5 are coaxially disposed in the pathof the air flow B between the nozzle 1 and the shell 6. The innermostbafile 3 is of V-shaped cross-section so as to form a converging innersurface 3a and a diverging outer surface 3b. The vertex of the V,pointing in the upstream direction of flow, forms a sharp annular ridge30 substantially in the plane of the nozzle outlet 1a. The bafile 3 isalso advantageously provided with peripherally spaced perforations 3d tohelp create some circulation in the forward space within the V (see alsoFIGS. 3 and 4). The outer baflles 4 and 5 are of frustoconical shape andlie parallel to the diverging surface 3b of inner baflie 3. Thus thereare defined between the bafiles 3, 4 and 5 a pair of diverging annularchannels 8 and 9, the apex angle of these channels and of the conicallydiverging surfaces of baflles 3, 4 and 5 having been designated b. Thebaffles are fixedly supported from the shell 6 by suitable stays 10 ofsmall air resistance so as to be spaced from the nozzle 1 and the shell6 to provide additional air passage. A pair of spark electrodes 2,energizable over an ignition circuit not further illustrated, aredisposed in the space between nozzle 1a and baffle surface 3a to lightthe flame of the burner.

The outer baflles 4 and 5 have upstream edges 4a and 5a which arerelatively offset in axial and radial direction so that the air layersdeviated into the channels 8 and 9 are of substantially constant widthd; thus, the radial staggering of these edges relatively to each otherand to ridge 3c may be such that, as shown, they lie on a rearwardextension of the forwardly converging surface 30. It is not absolutelynecessary that the downstream edges 3e, 3], 4b, 5b of the three bafl'lesterminate all in the same plane as shown in FIG. 1; channels 8 and 9should, however, be long enough to prevent the flow of any airtherethrough in the axial direction.

In operation, the oncoming air divides at ridge 30 substantially withoutturbulence into a primary flow B deflected inwardly by baflle surface 3aa secondary flow B directed outwardly by baffles 31), 4 and 5, and athird flow B passing directly from source 7 through the annularclearance between battle 5 and shell 6. Whereas the primary flow B joinsthe fuel spray A in the vicinity of nozzle outlet 1a, the secondary flowB passes together with the third flow B along the inner wall 6a of shell6 until it strikes an inturned ledge 6b of the shell at the open endthereof and is deflected inwardly and slightly rearwardly toward theaxis of cone A. Ledge 61) forms with shell wall 6a a rounded cornerwhose angle 0 may be close to as shown, though it could also be anobtuse angle.

It will be apparent that the converging surface 3:: of bafile 3 promotesthe circulation of air in the vicinity of nozzle 3 in a sensecounteracting the suction created by air flow B so as to minimize orprevent carbonization of both the nozzle outlet 1a and the bafllesurface 3b. The air flow past the baflles 3 to 5 will be substantiallylaminar since the diversion of the secondary air through channels 8 and9 reduces the possibility of turbulence within an axial plane. Ifdesired, however, a certain rotary twist may be imparted to the airstream B by means of suitable vanes as described hereinafter withreference to FIG. 3. Substantially all the air delivered by blower 7will be admixed with the fuel spray A, partly directly via path B andpartly over the circuitous path B so that the burner will operate atmaximum efliciency. The flame main tained forwardly of nozzle 1 will bedetached from its outlet 1a by the flow-directing action of bafflesurface 3a.

The intensity and character of the flame will, of course, be controlledby the rates by which air and fuel are delivered to the interior ofshell 6 and nozzle 1, respectively. Inmany instances it will also beadvantageous to be able to control the size of the flame by changing thewidth of the discharge end of the shell, eg with the aid of a manuallycontrollable iris-type diaphragm 11.

In FIG. 2 I have shown an otherwise identical burner in which thebaflles 3', 4, 5' have tubular extensions 23, 24, 25 with inturnedledges 23a, 23b, 23c terminating along the periphery of the cone A todischarge the secondary air substantially radially into the cone.

FIG. 3 illustrates the possibility of omitting the deflecting edge 6b ofthe previous embodiments, the nozzle outlet 1a being here so designedthat the diameter of the cone A at the mouth of shell 6' equalssubstantially the shell diameter. Thus the axially flowing secondary airB mingles with the fuel spray of cone A at a location where this sprayis substantially attenuated so as to be readily penetrated by the air.FIG. 3 also illustrates the provision of vanes 12 for setting the airflow B in rotation about the axis of the cone A.

In certain cases, particularly with a high-power blower, it will bedesirable to replace the baflle 3 or 3 of the preceding embodiments byan annular disk 13 positioned forwardly of the upstream edges 4a, 5a ofthe outer baflles 4 and 5 (or their modifications 4' and 5'). This hasbeen illustrated in FIGS. 5 and 6 which also show two circular arrays ofperforations 13a, 13b provided in the baflle plate 13 for the purposementioned in connection with perforations 3d. With batfle plate 13disposed slightly downstream of the nozzle outlet 1a, the flame willagain be detached from the nozzle to avoid the deposit of soot thereon.The system operates otherwise in substantially the manner previouslydescribed.

Further modifications of the arrangement described and illustrated,including substitutions and combinations of compatible features fromdifferent embodiments, are of course possible and are intended to beincluded in the spirit and scope of the invention as defined in theappended claims.

I claim:

1. In an oil burner, in combination, a substantially cylindrical shellhaving an open end, a source of axial air flow opening into said shellat a location forwardly of said open end and trained toward the latter,fuel-supply means including a tubular nozzle extending axially withinsaid shell at a location intermediate said source and said open end,said nozzle having an outlet disposed ahead of said open end fordischarging a substantially conical stream of atomized fuel toward saidopen end and centrally symmetrical annular baffle means spacedlysurrounding said nozzle in the region of said outlet for intercepting anouter part of said air flow and deflecting it outwardly toward the innerwall of said shell while giving passage to a nonrotating inner part ofsaid air flow through an annular clearance separating said bafile meansfrom said nozzle whereby said inner part mingles with said conical fuelstream just beyond said outlet, said baflle means having a forwardlyconverging inner frustoconical surface for guiding said inner parttoward the nozzle axis and at least one forwardly diverging outerfrustoconical surface for directing said outer part as a diverginglaminar flow toward said inner wall and thence as a cylindrical flow c0-axial with said inner wall toward said conical fuel stream forintermingling therewith at a location close to said open end andsubstantially beyond its zone of merger with said inner part, said innerand outer frustoconical surfaces meeting at a flow-dividing ridge facingtoward said source.

2. The combination defined in claim 1 wherein said baflle means isprovided with an annular array of circular openings along saidflow-dividing ridge for giving passage to axial streams of supplementalair around said inner part.

3. The combination defined in claim 1 wherein said ridge is locatedsubstantially in the plane of said outlet.

4. In an oil burner, in combination, a substantially cylindrical shellhaving an open end, a source of axial air flow opening into said shellat a location forwardly of said open end and trained toward the latter,fuel-supply means including a tubular nozzle extending axially withinsaid shell at a location intermediate said source and said open end,said nozzle having an outlet disposed ahead of said open end fordischarging a substantially conical stream of atomized fuel toward saidopen end, centrally symmetrical annular baffle means spacedlysurrounding said nozzle in the region of said outlet for intercepting anouter part of said air flow and deflecting it outwardly toward the innerwall of said shell while giving passage to a nonrotating inner part ofsaid air flow through an annular clearance separating said baflle meansfrom said nozzle whereby said inner part mingles with said conical fuelstream just beyond said outlet, said baflle means having a forwardlyconverging inner frustoconical surface for guiding said inner parttoward the nozzle axis and at least one forwardly diverging outerfrustoconical surface for directing said outer part as a diverginglaminar flow toward said inner wall and thence as a cylindrical flowcoaxial with said inner wall, and annular guide means within said shellclose to said end for deflecting said cylindrical flow radially inwardlytoward said conical fuel stream for intermingling therewith at alocation substantially beyond its zone of merger with said inner part,said inner and outer frustoconical surfaces meeting at a flow-dividingridge facing toward said source.

5. In an oil burner, in combination, a substantially cylindrical shellhaving an open end, a source of axial air flow opening into said shellat a location forwardly of said open end and trained toward the latter,fuel-supply means including a tubular nozzle extending axially withinsaid shell at a location intermediate said source and said Open end,said nozzle having an outlet disposed ahead of said open end fordischarging a substantially conical stream of atomized fuel toward saidopen end, and a set of coaxial centrally symmetrical annular bafllesseparated by a first annular clearance from the inner annular wall ofsaid shell and spacedly surrounding said nozzle in the region of saidoutlet for intercepting an intermediate part of said air flow anddeflecting it outwardly toward the inner wall of said shell while givingpassage to an outer part of said air flow through said first clearanceand to a nonrotating inner part of said air flow through a secondannular clearance separating said bafiles from said nozzle whereby saidinner part mingles with said conical fuel stream just beyond saidoutlet, said baflies including an inner baflle with a forwardlyconverging frustoconical surface for guiding said inner part toward thenozzle axis, said baffles further including several concentric outerbaffles with parallel frustoconical surfaces defining a plurality ofjuxtaposed frustoconical channels for directing said intermediate partas a plurality of parallel laminar flows of outwardly diverging shapetoward said inner wall, and thence together with said outer part as acylindrical flow coaxial with said inner wall toward said conical fuelstream for intermingling therewith at a location close to said open endand substantially beyond its zone of merger with said inner part, saidinner baflle and the innermost outer baffle meeting at a flow-dividingridge facing toward said source.

6. In an oil burner, in combination, a substantially cylindrical shellhaving an open end, a source of axial air flow opening into said shellat a location forwardly of said open end and trained toward the latter,fuel-supply means including a tubular nozzle extending axially withinsaid shell at a location intermediate said source and said open end,said nozzle having an outlet disposed ahead of said open end fordischarging a substantially conical stream of atomized fuel toward saidopen end, a set of coaxial centrally symmetrical annular bafliesseparated by a first annular clearance from the inner annular wall ofsaid shell and spacedly surrounding said nozzle in the region of saidoutlet for intercepting an intermediate part of said air flow anddeflecting it outwardly toward the inner wall of said shell while givingpassage to an outer part of said air flow through said first clearanceand to a nonrotating inner part of said air flow through a secondannular clearance separating said baflies from said nozzles whereby saidinner part mingles with said conical fuel stream just beyond saidoutlet, said baffies including an inner baflle with a forwardlyconverging frustoconical surface for guiding said inner part toward thenozzle axis, said baffles further including several concentric outerbafl'les with parallel frustoconical surfaces defining a plurality ofjuxtaposed frustoconical channels for directing said intermediate partas a plurality of parallel laminar flows of outwardly diverging shapetoward said inner wall, and annular guide means within said shell closeto said end for deflecting said cylindrical flow radially inwardly andthence together with said outer part as a cylindrical flow coaxial withsaid inner wall toward said conical fuel stream for 15 interminglingtherewith at a location substantially beyond its zone of merger withsaid inner part, said inner baffle and the innermost outer bafiiemeeting at a flow-dividing ridge facing toward said source.

References Cited by the Examiner UNITED STATES PATENTS 1,706,316 3/1929Norton et al 158-76 X 1,855,187 4/1932 Hyoslef 15876 1,953,483 4/1934Higinbotham 1581.5 X 2,301,060 11/1942 Livar 15876 2,782,738 2/1957Zoller 11028 FOREIGN PATENTS 839,267 6/ 1960 Great Britain. 168,865 7/1934 Switzerland.

FREDERICK L. MATTESON, JR., Primary Examiner.

PERCY L. PATRICK, MEYER PERLIN, JAMES W. WESTHAVER, ROBERT A. OLEARY,Examiners.

1. IN AN OIL BURNER, IN COMBINATION, A SUBSTANTIALLY CYLINDRICAL SHELLHAVING AN OPEN END, A SOURCE OF AXIAL AIR FLOW OPENING INTO SAID SHELLAT A LOCATION FORWARDLY OF SAID OPEN END AND TRAINED TOWARD THE LATTER,FUEL-SUPPLY MEANS INCLUDING A TUBULAR NOZZLE EXTENDING AXIALLY WITHINSAID SHELL AT A LOCATION INTERMEDIATE SAID SOURCE AND SAID OPEN END,SAID NOZZLE HAVING AN OUTLET DISPOSED AHEAD OF SAID OPEN END FORDISCHARGING A SUBSTANTIALLY CONICAL STREAM OF ATOMIZED FUEL TOWARD SAIDOPEN END AND CENTRALLY SYMMETRICAL ANNULAR BAFFLE MEANS SPCEDLYSURROUNDING SAID NOZZLE IN THE REGION OF SAID OUTLET FOR INTERCEPTING ANOUTER PART OF SAID AIR FLOW AND DEFLECTING IT OUTWARDLY TOWARD THE INNERWALL OF SAID SHELL WHILE GIVING PASSAGE TO A NONROTATING INNER PART OFSAID AIR FLOW THROUGH AN ANNULAR CLEARANCE SEPARATING SAID BAFFLE MEANSFROM SAID NOZZLE WHEREBY SAID INNER PART MINGLES WITH SAID CONICAL FUELSTREAM JUST BEYOND SAID OUTLET, SAID BAFFLE MEAN HAVING A FORWARDLYCONVERGING INNER FRUSTOCONICAL SURFACE FOR GUIDING SAID INNER PARTTOWARD THE NOZZLE AXIS AND AT LEAST ONE FORWARDLY DIVERGING OUTERFRUSTOCONICAL SURFACE FOR DIRECTING SAID OUTER PART AS A DIVERGINGLAMINAR FLOW TOWARD SAID INNER WALL AND THENCE AS A CYLINDRICAL FLOWCOAXIAL WITH SAID INNER WALL TOWARD SAID CONICAL FUEL STREAM FORINTERMINGLING THEREWITH AT A LOCATION CLOSE TO SAID OPEN END ANDSUBSTANTIALLY BEYOND ITS ZONE OF MERGER WITH SAID INNER PART, SAID INNERAND OUTER FRUSTOCONICAL SURFACES MEETING AT A FLOW-DIVIDING RIDGE FACINGTOWARD SAID SOURCE.